Process of defecating raw cane-sugar or cane-sugar syrup.



M. WEINRIGH. PROCESS or DEFEGATING RAW CANE summon CANE SUGAR SYRUP.

APPLICATION FILED FEB.]., 1913,

A M W, m w m m m m J .r w m m Mm a m P sb v N w 3 m 40, 7 7 6 M 5 m 0, w1 H W in "outrun strains PATENT union.

MOB-I2] HEINRICH, 0F YONKIFIIRS, NEW YGRK.

To all whom it may concern:

Be it known that 1, Menu l'Vni'Nnron', a citizen of the United States,residing at Yonkers, in the county of Westchester and State of New York,have invented certain new and. useful Improvements in Processes of Del",-.catiog Haw (lane-Sugar or Canet r'ugar Syrlui, of which the followingis a specification.

lily invention. relates to process of defeeating raw cane sugar, or canesugar syrup; it a variation of my prior Patents No. 822,171, dated May29/06 and No. "(11,603, dated Oct. 2]., 1902. It is further an,improvement on the ordinary defecating process as generally used in canesugar refineries.

The n'ocess generally practised today for delineating raw cane sugar, orcane sugar syrup, may be said to consist of: 1, either dissolving theraw sugar to about 30 136., adding from to of lime in shape of mill; oflime, then neutralizing the lime by means of phosphoric acid, heatingthe solu tion to about 90 C. and finally filtering it through mechanicalfilters, or 2, dividing first the raw sugar, by washing it in cenlri'fugal ll'lilCllillfiS with water or slearn, into a washed sugar of 98 to99 purity, and a wash syrlilp of 70 to 80 purity. The washed sugar isthen melted. to about 30 36., some milk of lime added, 'neul-raliz'zcdwith phosphoric acid and filtered. The washed syrup is diluted to about37 136., from 0.5 to 0.71 of lime in shape oi milk of lime added andthen neutralized with phosphoric acid and filtered. It is well knownthat the puritication and clecolorization obtained by this mode ofde'liecating is insignificant, the object of it being mainly to vobtainbright solutions of uniform neutrality, or slight alkalinity,beforefiltering them over honcblack.

ll'iy present invention comprchciuls a new defilug prowess by which, ata small eiv'tra expense on lime, I remove 50 to (30% of all color, 80 to50% of the ash, all. of the iron pnesent, and ill) to 50% ol. theorganic impurities. I also reduce the vil-lcosity and destroypractically none of the glucose or fruit sugar pi sen-t.

By the use or": my present process, either the subsequent application ofchar can be much reduced, or, when using the same perhearings of chm" asheretofore, the char Specification of Letters Patent.

Application filed February 1, 1913.

035 DEFECAIEING RAW CANE-SUGAR O3, CANE-SUGAR SYRUP.

Patented Jan. 20, 1914. Serial 139. 745,624.

filtered solutions will be purer and lighter in color and free fromiron, which insures better products and an increased yield of refinedsugar.

\Vith the above and other objects in view my invention consists of theprocess oi defec-ating raw cane sugar, or cane sugar syrup, which I willhereinafter fully describe and point out in the claims.

In the accompanying drawings I illus" ing tank connected thereto. Fig. 2is an enlirged detail ot one of the toothed t disks. F.

In carrying out my present invention, I proceed substantially along the'lollowing lines:

(.l) [)cfcmtiny amour/loo cum: row .s-ug mnlhe raw sugar to be treatedis designed to be fed continuously from a bin or an elevator into oneend of a suitable horixontally disposed mixer, A, as shown in Fig. l. Apipe. 11. connects with the mixer and through this pipe runscontinuously some water into the mixer, this water amounting: loS to lOQi. of the weight of the sugar and having a temperature of 20 to 30" Themixer, which may have a length of say 12 feet and a depth and width of 3to l l'ect, is provided with two shalts, s, of which one only is shownin the drawing, said shafts carrying toothed disks, l", as shown in Fig.2, which are arranged side by side on the shafts, in close order, andwhich, when revolving against each other, will ruin the sugar with thewater to a magma. 1 part. of the'xnixture is covered with a suit-- ablehood, l3, and inside of this hood pultion is arranged a vibratingscreen, (I, which is adapted to be agitated by a suitable crank shallturned from the outside by an approprialc toothed wheel, I), orotherwise. Upon the aforesaid screen a pipe, 0, is adapted tocontinuously deliver powdered lime derived from a bin, D, or otherreceiver and fed to the pipe therefrom by means of a screw conveyer, (Z,or some other appropriate feeding means. The mixer has connected withone end an open trough, 6, adapted to deliver the overflowing magma fromthe mixer, A, to a set of two or more defecating tanks, of which one isshown at E in Fig. 1, said mixer being also provided with a pipe, f,which connects-with the defecating tank and is provided with a slidingorother valve, 9, for emptying the mixer when desired, into one or more ofthe defecating tanks. These tanks are of cylindrical shape andare closedon the top from which the vapor pipe, 71., leads to the open air. Theyare provided with stirrers 2', 6, 2' etc., with a steam worm, is, andwith appropriate distributing devices for carbonic acid gas Z, Z. Thetanks shall have a height of about 12 feet and may have a diameter offrom 7 to 10 feet. To the raw sugar magma which has been formed in thefore-part of the mixer, A, is added continudusly to the vibratingscreen, C, acertain amount; of finely powdered caustic lime (02.0). Thisamount shall vary, according to the quality of the raw sugar, from 1 to2% of the weight of the sugar. By the closely set disks of the mixer,the lime powder becomes intimately mixed with the magma. In the syrup,surrounding the sugar crystals, the caustic lime will slake only slowlyand will have time to act very energetically in. its caustic state oncolor and impurities. The mixer shall be large enough to hold the magmaafter the adding of the lime for about twenty minutes, thus iving thelime sufiicient time to act thoroughly on impurities and color. Insteadof powdered caustic lime, powdered dry slaked lime or a thick milk oflime may be used, but powdered caustic lime gives the best results, asset forth in my aforesaid former patents. The lime treated magma runscontinuously and alternately by overflow through the trough, 6, into oneof the defecating tanks, It,- which have been previously filled abouttwo feet high with water of a temperature not exceeding 30 C. As soon asthe magma begins to drop into the tank, the stirrers, f, f, 7, etc., areset in motion and carbonic acid gas (CO is pumped into the solutionthrough Z, Z. This gas is sucked by a pump through a gas Washer orscrubber, from the steam boiler fiues costing therefore nothing. Itcontains only from 8 to 1.2% of CO, and the pump and washer have to betherefore correspondingly large. In large refineries, and where goodlimestone can be procured at a reasonable price, such limestone may beburned to lime in a kiln, and the CO gas drawn from the kiln, as done inall beet sugar factories. The amount of lime to be neutralized by it is,however, comparatively small. By beginning with the carbonation as soonas the magma begins to dissolve in the water, a large. portion of theline is neutralized while present in a much diluted solution, thusfacilitating greatly thecarbonation process. By the stirrers, the-particles of the sucrate of lime, which have been formed by the actionof the caustic lime, are kept afloat, their decomposition by the ()0 gasis thereby much facilitated and their settling on the bottom of thetanks prevented. hen from 3 to 3-1; feet of magma has been run into thetank, thus making the column of the solution 5 to 5% feet high and of adensity of about 50 Brix after completed neutralization anddecomposition the infiow of the magma is stopped and carbonation carriedon to 0.14 to 0.12 alkalinity. This mode ofcarbonating, even with thingas and a final solution of about 50 Brix, takes less than one hour,while it would take, at the low temperature em ployed, several hours ifthe magma would be diluted in the beginning to about 50 Brix and then,without stirring, carbonated,

giving besides a much less purified finished solution than by a quickcarbonation. As soon as this alkalinity is reached, the gas. is stoppedin order to avoid the redissolving of color and impurities, which, aswell known, will take place if carbonation is carried below a certainpoint, which-point, in a solution of 50 Brix, is 0.14 to 0.12alkalinity. This is also the reason why, in order to attain a goodpurification, a second carbonation, to nearly neutrality, is requiredafter having first separated the lime-precipi: tate of the firstcarbonation from the solution. I have, however, found that theredissolving of impurities and thereby the second carbonation'and doublefiltration can be avoided by neutralizing the remaining alkalinity witha suitable acid such as phoslinity of the 0.14 to 0.12 has been reachedand the gas stopped, I add .sufiicient dilute phosphoric acid, whilestirring is kept on, to bring the solution to slight alkalinity, or fullneutrality. I then beat, by means of the steam coil, 71, under constantstirring to about 90 C. and filter as usual through mechanical filters.The amount of phosphoric acid usedin this way is about the same as thatused in the ordinary defecation and since the CO gas is procured free ofcost, either from the fines or from a lime kiln, the only extra expenseis that for the additional amount of lime and the pumping of the gas. Bythe special application of the lime, the special way'of carbonating inpurities is attained in a simple and cheap way. I

its

(B) Defecating washed raw cane sugar and its wash syrup-This requires,as it does with the ordinary method, two sets of (letecators. The washedsugar, which has generally a purity of about 99 can be either defecatedas it is done at present, or, as described above for unwashed raw sugar,using, however, only about $78 of lime powder of weight 0f sugar. Thebagdiltered liquor will be very pure and light in color and very litIIechar will make it water white. The wash syrup is either pumped or runsby gravity continuously, in its cold state, from the wash centritugalsinto the mixer, A, Where it is 1n'ii e :l,(without add ing any water),according to its purity, with 2 t 3% of its weight of lime powder. Theheavier the syrup, the better will act the caustic lime on color andimpurities. The lime treated syrup runs, like the raw sugar magma, byoverflow into the de'tecators, E, and is treated there exactly as theraw sugar magma. Color and impurities being'here in a concentratedstate, the action of the treatment is more marked than on raw sugar, andthe bag filtered washings can be sent over the char much purer and muchlighter in color than heretofore, having lost besides, much of theirviscosity.

It is obvious that not alone wash syrups from cane raw sugar, but anyother cane syrup can be purified to advantage in the specified. way.

This process can be also employed to good advantage on cane sugarplantations on which either whitc' sugar or raw sugar is manufactured,hen white sugar is made the second. and third product raw sugar of thefactory, to which may be added raw sugar from outside sources, is mixedin the mixer with about 10% of its weight of unheated raw can juice,coming from the mills, into a. magma and then treated with limeamounting to 1 to 1-1;% of weight of cane ground, as specified above.The lime treated magma is then run in the same way into the defecationtanks, which had been filled previously about 4 feet high with an heatedraw cane juice instead of water. The subsequent treatment is the same asde-- scribed above. In a factory, making only raw sugar, about 50 to' ofall the first molasses or green syrup produced, is

pumped into the mixer where it is mixed with from 1 to 15% of lime ofweight of cane ground, and then run into the defecation tanks, which hadbeen likewise filled previ ously about 4 feet high with unheated rawcane juice. The subsequent treatment is likewise the same as specifiedabove. By treating in this way all the raw cane juice coming from themills, the finished juice will be, of course, considerably thinner than50 Brix and its density will vary between 20 to 30 Brix.

Having thus described my invention what I claim as new and desire tosecure by Let ters Patent is 1. The process of defecating raw canesugar, or cane sugar syrup, while in a cold state consisting essentiallyin mixing intimately therewith a small percentage of finely dividedlime, then slowly running the treated material into water into whichsimultaneously carbonic acid gas is admit-ted, thus carbonating thegreater part in a much diluted state, discontinuing the admission of thegas before any re-dissolv ing of impurities begins, then neutralizingthe solution fully by means of a suitable acid, thus saving the secondcarbonation and second filtration, and finally heating and, filteringthe solution.

2. The process of defecating raw cane sugar, or cane sugar syrup, whilein a cold state, consisting essentially in mixing intimately therewith asmall percentage of finely divided lime, then running slowl the treatedmaterial into unheated raw tune juice, into which simultaneouslycarbonic acid is admitted, thus carbonating the greater part in a muchdiluted state, discon' tinuing the admittance of the gas before anyre-dissolving of impurities begins, then neutralizing fully by means ata suitable acid thus saving the second carbonation and secondfiltration, and finally heating and filtcring the solution. 1

3. The roccss of defecatin raw cane} sugar, or cane sugar syrup, whilein a cold state, consisting essentially in mixing intimately therewith asmall percentage of finely powdered caustic lime, then running thetreated material slowly into water of about 30 G. into whichsimultaneously, un-

der continuous stirring of the solution, carbonic acid gas is admitted,discontinuliiflthe admittance of the gas before any re-diSBOlving ofimpurities begins. then neutralizing fully by a suitable acid, thussaving the second carbonation and second filtration, and finally heatingand filtering the solution.

4. The neutralization of limed cane sugar solutions in the coldconsisting in carbonating such solutions to the point before redissolving of impurities begins, then neutralizing fully by a suitableacid, thus saving the second carbonation and second filtration, andfinally heating and filtering the' solutions.

In testimony whereof I atlix my signature in presence of two witnesses.

MORIZ WEINRICH. WVitnesses: EowAim G. CDNICK,

Grouse A SMITH.

